Condenser



1938 w. DUBILIER 2,127,352

CONDENSER Original Filed Oct. 12, 1932 Fig].

gill/0m Dub/'l/elr 6M, ML

ATTORNEYS 95% m 2 w M ha m I 3 m 2 4 8 y m L Q M. Q @iSi I g 5 INVENTOR ll 6 Patented Aug. 16, 1938 UNITED-STATES PATENT-OFFICE CONDENSER Application October 12, 1932, Serial No. 637,415

Renewed July 3, 1937 a 13 Claims. (Cl. 175-41) This invention relates to condensers and similar electrical devices, and containers therefor, and more particularly to such devices when associated with a liquid, such as an insulating oil.

For the purposes of this specification the term condenser includes other electrical devices which will function when sealed within a container; and the term oil includes other liquid insulating or impregnating materials.

It is important that the condenser be well supported within its container, and the requisites of the container are that it keep the oil in, keep moisture out, and that it afford mechanical protection and support.

Two types of such containers are in common use, one of which is formed of thin sheet metal having its seams soldered, as in a sardine can, and is therefore limited to small and light weight devices. Containers of this type are cheap but afford little mechanical protection-to the device enclosed therein and they are easily damaged, with consequent leakage. The other type is made of heavy metal to provide an oil tight container with sufficientmechanical protection. The cost of such containers is high, whether they are made with soldered or welded joints, or made seamless by drawing or casting; a large part of the cost being due to the necessity of making them tight to oil and moisture. Additional expense and dif- 30 ficulty "are involved in welding or soldering the cover on such a. container due to the large amount of heat absorbed by the heavy metal walls and the danger of injuring the condenser therein. In either type the scams or joints are directly ex- 35 posed to mechanical shocks which may break them and cause leakage.

The object of this invention is to make a container'which is easily sealed to oil and moisture and which gives greater protection against leakage and mechanical shocks than either type aforementioned, at less cost than the heavy type and occupying about the same or less space. A further object is to support a condenser within the container in fixed, spaced relation to the 45 walls.

The invention will be described in connection with the accompanying drawing showing one embodiment thereof and in which Fig. 1 is a view partly in section, of a container with a condenser and its support therein, according to the invention;

Fig. 2 shows the external appearance thereof on a smaller scale;

' Fig. 3 shows a support member; and

Fig. ,4 is a fragmentary sectional view corresponding to Fig. 1 but slightly spread and enlarged for clearness.

In the several figures like reference characters indicate like parts.

The container for' the condenser shown in Figs. 1 and 2 is provided with double walls consisting of a thin metal can I and an outer enclosure 2 of heavy metal. Cushioning material is disposed between the inner and outer walls preferably at the top and bottom, as illustrated by spacers 3 and 4, of cork, rubber composition or the like. The can I should be a snug fit within the enclosure 2 mm little space between their side walls, but if desired additional cushioning material may beinserted therebetweenw The spaces between the walls may be filled with melted compound indicated at 3a (Fig. 4), such as wax, in

lieu of spacers 3 and 4 or in combination therewith.

Since the inner can I is made of thin metal, such as tin, it is easily formed and soldered, thereby providing an oil and moisture tight enclosure for a condenser 5. The outer can 2 need not be oil tight, its chief purposes being to provide mechanical protection and support for the inner. can and the condenser. For this reason the enclosure 2 can be made very cheaply by bending up sheets of heavy metal and spot-welding the joints. A closure member or bottom cover 6 can be secured by a riveting or bending operation, or both; Preferably this cover consists of a metal plate having its sides 1 and 8 bent up to engage the corresponding sides 9 and ll! of enclosure 2 andhaving its end portions secured by eyelets H to projecting feet I! and I3 of the enclosure. For additional security, the corners M of cover 6 are bent down to engage the upper sides of projections l2 and I3. The projecting feet are thus made doubly thick with triple thickness at the corners,,to provide a rigid mounting base for the device.

Fig. 3 shows details of a portion of a support or sists of a number of oil filled sections l9 stacked 7 one above the other, each section having-foils of opposite polarity exposed at/opposite 'ends thereof. These condenser sections are stacked in the member IS with their foil ends projecting in the direction of extensions -lI-.and l8 respectively, and spaced therefrom. The sides of the sections may bear directly against the sides of the member it but insulating liners may be inserted between the bearing surfaces if desired. The support for the condenser is completed by another U-shaped member 20 which bears against the'top section of the condenser and is held in place by the bent-over ends II and 22 of member 18. Members l6 and 20 thereby form a clamp for the condenser sections which are preferably held under pressure while the ends II and 22 are bentover. Liners 23 provide insulation for the clamp. The can I is made sumciently long to provide spaces between the foil ends and the walls of the can so that, when the clamped condenser is within the can, the projections l1 and II keep the foil ends in spaced relation to the walls. Lateral movement of the condenser is prevented by the scribed, the cushioning effect between the two walls absorbs and distributes mechanical shocks, thereby preventing injury to the soldered seams of the inner wall so that they remain oil tight even though the device be subjected to mechanical abuse. The double-wall construction also prevents accidental puncture of the inner wall by sharp instruments, a frequent cause, of trousides of the member II and its projections l1 and I ll. The portions oi the \members It and 20 which project above the condenser prevent movement of the condenser in a vertical'direction.

The condenser sections are electrically connected by metallic strips, such as 24, extending from one section to another in the spaces between the foil ends and the walls of the container, such connections being made before the condenser is inserted in the can. In Fig. 1 all of the sections are connected in parallel, but series or series-parallel connections may be used or the sections may be connected to form separate groups. I

The members it and 20 provide and maintain suflicient space between the top of the condenser and the top of can i for terminals, such as 25 and 2G, and leads, such as 21 and 28, electrically connecting the terminals with the condenser. The terminals 25 and 26 are preferably secured to the top of the inner can I and insulated therefrom by means of insulating washers 28; holes in the can being made considerably larger than the terminals. The washers 29 are sealed by cement or varnish. The top of the outer can 2 is provided with openings 3i and is otherwise adapted to accommodate the washers and terminals. Suitable connecting lugs 32 are secured to the terminals for convenience in making electrical connections;

The above mentioned spaces between the to and sides of the condenser 5 and the can I are made no longer than is necessary to provide ble with tin can type containers. The protection afforded by the outer walls permits the use of thin metal for the oil tight portion of the container even though the enclosed electrical device has considerable size and weight. These advantages are obtained with a double-walled container having the same or smaller outside dimensions than a single walled container of the same inside dimensions because of-the space required for upstanding seams and thick welds to make the latter container'oil tight.

The manufacturing cost of such a doublewalled container is less than the cost of the heavy single-wall type due principally to the simplicity of its parts and the ease with which they are joined. The condenser can be sealed in the inner can without excessive heating thereof because of the small heat capacity of the thin room for the connecting strips and leads, thereby conserving space and oil. The fixed spacing provided by the condenser clamp permits small clearances with assurance that accidental contact of conductive parts with the walls will not occur. a

In assembling the condenser, the can I with the condenser and its clamptherein and with the terminals ailixed, is sealed up except for two all holes such as II. The can is then filled with hot oil (approximately 160 F.) through one of these holes, the air escaping through the other hole. The can is filled to within about Vath inch of the top and, while the oil is still hot, the holes are soldered over. when the oil cools a slight vacuum is created thereby permitting subsequent expansion and contraction of the oil without creating excessive pressure in the can and eliminating the necessity for a breather openas.

In a double-walled container, as above demetal walls. Joining the parts of the other enclosure presents no difficulty when the joints need not be oil'tight, and no heat is required to complete the outer enclosure after the condenser is placed therein. As an example, a heavy metal can of a certain size and made oil tight costs $2.50 plus-the labor required to seal the cover after the condenser is inserted therein, which operation is complicated by the large amount of heat required and consequent danger to the condenser. Compared to this cost, a doublewalled container of the same size costs only 30 or 31 cents, of which 12 M13 cents is the cost of the inner can and 18 cents is the cost of the outer enclosure.

' The manufacture of a container in accordance with this invention requires less expensive equipment and such equipment is more readily adapted to diiierent sized containers than the equipment required for the manufacture of oil tight. heavy metal containers.

I claim:

1. A container for an electrical condenser comprising an inner liquid-tight thin sheet-metal casing, an outer casing of relatively thick sheet metal and a meltable compound interposed between the casings and filling any open spaces between them and substantially adhering to their opposite faces.

2. An electrical condenser comprising an inner liquid-tight thin sheet-metal casing holding the condenser elements therein, an outer casing of relatively thicker sheet metal and slightly larger than and surrounding the inner casing, and a wax-like compound partially or wholly filling the space between the two casings and constituting a unitary filler means.

3. An electrical condenser comprising an inner liquid-tight, thin sheet-metal casing holding the condenser elements therein, an ,outer casing of relatively thicker sheet metal and slightly larger than and surrounding the inner casing, and a compound sufliciently liquid to be poured into said space between the two casings and becoming solid at normal temperature so as to constitute a unitary means for securely positioning and protecting the inner thin metal casing.

4. An electrical condenser comprising a conaiaassa denser body, a container for the condenser body formed of thin readily bendable metal having edge portions bent into tight-fitting engagement with adjacent portions of the container to form seams, sealing means continuously sealing all seams to provide a liquid-tight casing, said metal having sufficient rigidity to provide a self-supporting manipulable container unit; and an unsealed outer protective casing of relativelyrigid shock-resistant metal enveloping and closely fitting the container.

5. An electrical condenser comprising a condenser body, a container for the condenser body formed of thin readily bendable and solderable metal having edge portions crimped together to form seams, solder continuously sealing all seams of the container to provide a liquid-tight casing, said metal having sufficient rigidity to provide a self-supporting manipulable container unit; and an unsealed outer protective casing of relatively rigid shock-resistant metal enveloping and closely fitting the container.

6. An electrical condenser comprising an hermeticaliy sealed container formed of thin readily bendable metal, a condenser body mounted in the container and completely supported thereby, said metal having suflicient rigidity to provide, in combination with the condenser body mounted therein, a self-supporting ma'nipuiable container unit; and an unsealed outer protective casing of relatively rigid shock-resistant metal enveloping and closely fitting the container.

7. An electrical condenser comprising an hermetically sealed container formed of thin readily bendable metal, a condenser body mounted in the container and completely supported thereby, said metal having sufficient rigidity to provide, in combination with the condenser body, a self-supporting manipulable container unit; an unsealed outer protective casing of relatively rigid shock-resistant metal enveloping and closely fitting the container, and insulated terminals connected to the condenser body and accessible from the exterior of the protective casing.

8. An electrical condenser comprising an hermetically sealed container formed of thin relatively flexible metal, a condenser body mounted in the container, said metal having sumcient rigidity to provide, in combination with the condenser body, a self-supporting manipulable container unit; and an outer protective casing of relatively rigid metal enveloping and closely fitting the container, the protective casing being formed of a plurality of sections joined at spaced points to provide an unsealed mechanically strong casing.

9. An electrical condenser comprising a condenser body, a container for the condenser body formed of thin readily bendable metal having edge portions bent into tight-fitting engagement with adjacent portions of the container to form seams, sealing means continuously sealing all seams to provide a liquid-tight casing, said metal having suflicient rigidity to provide a self-supporting manipulable container unit; and an outer protective casing of relatively rigid metal enveloping and closely fitting the container, the protective casing comprising a body portion shaped to fit closely and substantially containuously over the sides and one end of the contamer, arranged to permit endwlse insertion of the container, and an end section adapted for connection to the body portion in position to cover the exposed end of the inner container after insertion thereof in the body portion, the outer casing sections being arranged to provide a mechanically strong unsealed casing for the container.

10. An electrical condenser comprising a condenser body, a container for the condenser body formed of thin readily bendable metal having edge portions bent into tight-fitting engagement with adjacent portions of the container to form seams, sealing means continuously sealing all seams to provide a liquid-tight casing, said metal having sumcient rigidity to provide a self-supporting manipulable container unit; an unsealed outer protective casing of relatively rigid metal enveloping and closely fitting the container, and cushioning means arranged between the casing and the container in position to prevent movement of the container in the casing, said means comprising yieldable material in extended contact with the walls of the container body to distribute over a substantial area of the container impacts transmitted through the casing.

11. An electrical condenser comprising a condenser body, a container completely enclosing the body, and means for mounting the condenser body in the container, comprising fiat members engaging the top, bottom and opposite sides of the condenser body and positioned in fiatwise' contact with the bottom and two opposite sides of the container, extending into engagement with the other opposite sides of the container at the bottom to maintain the condenser body against movement within the container.

12. An electrical condenser comprising a condenser body comprised of a plurality of flattened condenser rolls, a container, and a clamping forcement therefor, said'bottom being provided with upturned ends engaging the other sides of the container and arranged to maintain said sides in spaced relation to the ends of the condenser rolls.

13. An electrical condenser comprising a, condenser body, a container, and a clamping frame for mounting the body in the container, said frame comprising a U-shaped member ofsheet material extending along the bottom and opposite sides of the condenser body and in substantially continuous flatwise engagement with the juxtaposed sides of the container, 9. bottom member of sheet material extending across the bottom of the U-shaped member and having upturned ends engaging the other sides of the container in position to maintain the condenser body in spaced relation thereto, the bottom of the frame being in substantially continuous flatwise engagment' with the bottom of the container.

wnmm ppm. 

